With the development of the information industry, the technology that can transmit various kinds of large data at high speed has been required. In this respect, a multi-node system that adopts a plurality of nodes has been studied to remove a shade zone and extend coverage.
The multi-node system uses a plurality of nodes each of which may represent a base station, an access point, an antenna, an antenna group or a radio remote header (RRH). The plurality of nodes may be managed by one base station/base station controller which control and schedule the nodes' operation.
Distributed nodes connected with a single base station/base station controller through a cable or a dedicated line, wherein the single base station/base station controller manages a plurality of nodes located within a cell at predetermined intervals. This multi-node system may be regarded as a multiple input multiple output (MIMO) system in that distributed nodes can support a single user equipment or multiple user equipments by transmitting and receiving different data streams at the same time. In view of the MIMO system, the multi-node system is advantageous in that it can reduce a transmission power as a transmission zone is more reduced than that of the CAS due to nodes distributed at various locations within a certain geographical area. Also, the multi-node system can reduce path loss by reducing a transmission distance between a node and a user equipment, thereby enabling high rate transmission of data. As a result, the multi-node system can enhance transmission capacity and power efficiency of the cellular system, and can satisfy communication throughput of quality more relatively uniform than that of the CAS regardless of user location within the certain geographical area. Also, since the base station/base station controller(s) connected with a plurality of distributed nodes cooperates in the multi-node system, signal loss is reduced, and correlation and interference between the antennas are reduced, whereby a high signal to interference to noise ratio (SINR) can be obtained.
As described above, in order to reduce facility costs of the base station and maintenance costs of a backbone network in a next generation mobile communication system and at the same time extend service coverage and improve channel capacity and SINR, the multi-node system can be a new basis of cellular communication by being compatible with the existing CAS or replacing with the CAS.